io.undertow.websockets.extensions

Interface ExtensionFunction

All Known Implementing Classes:

CompositeExtensionFunction, NoopExtensionFunction, PerMessageDeflateFunction

public interface ExtensionFunction

Base interface for WebSocket Extensions implementation.

It interacts at the connection phase. It is responsible to apply extension's logic before to write and after to read to/from a WebSocket Endpoint.

Several extensions can be present in a WebSocket Endpoint being executed in a chain pattern.

Extension state is stored per WebSocket connection.

Author:

Lucas Ponce

Field Summary

Fields

Modifier and Type	Field and Description
static int	RSV1 Bitmask for RSV1 bit used in extensions.
static int	RSV2 Bitmask for RSV2 bit used in extensions.
static int	RSV3 Bitmask for RSV3 bit used in extensions.

Method Summary

Modifier and Type	Method and Description
void	dispose() Dispose this function.
boolean	hasExtensionOpCode() Validate if current extension defines a new WebSocket Opcode.
PooledByteBuffer	transformForRead(PooledByteBuffer pooledBuffer, StreamSourceFrameChannel channel, boolean lastFragmentOfMessage) Transform the supplied buffer per this extension.
PooledByteBuffer	transformForWrite(PooledByteBuffer pooledBuffer, StreamSinkFrameChannel channel, boolean lastFrame) Transform the supplied buffer per this extension.
int	writeRsv(int rsv) Add RSV bits (RSV1, RSV2, RSV3) to the current rsv status.

Field Detail

RSV1

static final int RSV1

Bitmask for RSV1 bit used in extensions.

See Also:

Constant Field Values

RSV2

static final int RSV2

Bitmask for RSV2 bit used in extensions.

See Also:

Constant Field Values

RSV3

static final int RSV3

Bitmask for RSV3 bit used in extensions.

See Also:

Constant Field Values

Method Detail

hasExtensionOpCode

boolean hasExtensionOpCode()

Validate if current extension defines a new WebSocket Opcode.

Returns:

true if current extension defines specific Opcode false is current extension does not define specific Opcode

See Also:

WebSocket Base Framing Protocol Reference

writeRsv

int writeRsv(int rsv)

Add RSV bits (RSV1, RSV2, RSV3) to the current rsv status.

Parameters:

rsv - current RSV bits status

Returns:

rsv status

transformForWrite

PooledByteBuffer transformForWrite(PooledByteBuffer pooledBuffer,
                                   StreamSinkFrameChannel channel,
                                   boolean lastFrame)
                            throws IOException

Transform the supplied buffer per this extension. The buffer can be modified in place, or a new pooled buffer can be returned (in which case be sure to free the original buffer

Parameters:

pooledBuffer - Buffer to transform

channel - working channel

Returns:

transformed buffer (may be the same one, just with modified contents)

Throws:

IOException

transformForRead

PooledByteBuffer transformForRead(PooledByteBuffer pooledBuffer,
                                  StreamSourceFrameChannel channel,
                                  boolean lastFragmentOfMessage)
                           throws IOException

Transform the supplied buffer per this extension. The buffer can be modified in place, or a new pooled buffer can be returned (in which case be sure to free the original buffer

Parameters:

pooledBuffer - Buffer to transform

channel - working channel

lastFragmentOfMessage - If this frame is the last fragment of a message. Note that this may not be received for every message, if the message ends with an empty frame

Returns:

transformed buffer (may be the same one, just with modified contents)

Throws:

IOException

dispose

void dispose()

Dispose this function. Called upon connection closure